This application is a national stage application filed under 35 U.S.C. 371 of PCT/EP99/05426, filed Jul. 29, 1999.
The invention relates to the use of cyclopentabenzofuran derivatives for the production of a medicament for the therapy of NF-xcexaB-dependent diseases.
Extracts of the plant Aglaia elliptifolia exhibit antileukemic properties. The first active compound identified was a dihydrocyclopentabenzofuranol derivative called rocaglamide (J. Chem. Soc., Chem. Commun. 1982, 1150; US 4 539 414). After this, several studies appeared on synthesis experiments which were finally also successful. Only 10 years after the isolation of rocaglamide were its insecticidal properties described (Pestic. Sci. 36 53 (1992); Phytochemistry 32, 67 (1993)) and after that in another species, Aglaia odorata, another three derivatives only differing in one substituent were found (Phytochemistry 32, 307 (1993)).
Later, for example, from the species Aglaia roxburghiana, the first four fused derivatives of rocaglamide were isolated (WO 96/04 284), then numerous further new derivatives and their pharmacological properties were described (cf., for example, J. Nat. Prod. 59, 650 (1996); Tetrahedron 52 6931 (1996); Phytochemistry 44, 1455 (1997); Phytochemistry 45 1579 (1997); Z. Naturforsch., C: Biosci. 52, Tetrahedron 52, 17625 (1997); B. W. Nugroho, Thesis, Bayer. Julius-Maximilian Univ. Wxc3xcrzburg, 1997, WO 97/08 161 A1, J. Nat. Prod. 61, 1482 (1998), Tetrahedron 53, 17625 (1997).).
An important step in many inflammatory processes is the translocation of the protein xe2x80x9cnuclear factor kappa Bxe2x80x9d, in brief NF-xcexaB, into the cell nucleus and the stimulation of the expression of the genes caused thereby, whose products are responsible for inflammatory reactions (Trends Pharmacol. Sci. 18, 46 (1997)). For example, in asthma the nonbeneficial, excessive (non self-limiting) production of these proteins is responsible for the intensification and maintenance of the inflammatory process and the unpleasant to life-threatening symptoms of this disease associated therewith. Because the long-term treatment with glucocorticoids corresponding to the present state of the art is affected by some disadvantages, NF-xcexaB is seen as a compelling target for the development of new anti-inflammatory active compounds against asthma.
It has now been found that the cyclopentabenzofuran derivatives of the formula (I): 
in which
[A] R1 represents hydrogen,
R2 represents methoxy,
R3 represents hydrogen or
R2 and R3 together represent xe2x80x94OCH2Oxe2x80x94,
R4 represents methoxy,
R5 represents hydroxyl, OCHO or acetoxy,
R6 and R7 in each case represent hydrogen or
R5 and R6 together represent oxygen (oxo) or hydroxyimino,
R8 represents xe2x80x94COOR12 or xe2x80x94CONR13R14, in which
R12 and R13 represent hydrogen or methyl and
R14 represents hydrogen, methyl, 4-hydroxybutyl or 2-tetrahydrofuryl,
or
R8 represents a radical of the formula: 
R5 and R8together represent a group of the formulae (a) or (b): 
where the linkage site adjacent to the N atom corresponds to R5 and moreover R6 and R7 together represent a direct bond,
R9 represents phenyl,
R10 represents methoxy,
R11 represents hydrogen, hydroxyl, 2-methoxy or 2-rhamnosyl, or
R10 and R11 are adjacent and together represent xe2x80x94OCH2Oxe2x80x94, or
R15 represents hydroxyl, methoxy or ethoxy,
R16 represents hydrogen, hydroxyl or methoxy,
[B] R1, R3 and R8 in each case represent hydrogen,
R2 and R4 in each case represent methoxy,
R5 represents hydroxyl,
R6 and R7 in each case represent hydrogen or
R5 and R6 together represent oxygen (oxo group),
R9 represents phenyl,
R10 represents methoxy,
R11 represents 2-methoxy or 2-rhanmosyl, or
R10 and R11 are adjacent and together represent xe2x80x94OCH2Oxe2x80x94,
are suitable as inhibitors of nuclear factor kappa B (NF-xcexaB)-mediated gene expression for the therapy of pathophysiological processes.
The substances utilizable according to the invention are known from the above-mentioned literature.
Examples of the substances of the formula (I) utilizable according to the invention are the compounds (I-1) to (I-45), which are listed below.
Of the above-mentioned substances of the general formula (I), the compounds I-1, I-2, I-3, I-4, I-5, I-6, I-8, I-10, I-12, I-13, I-15, I-19, I-20, I-22, I-26, I-28, I-32, I-33, I-42 are preferred.
The substances utilizable according to the invention are low molecular weight inhibitors which selectively inhibit nuclear factor kappa B (NF-xcexaB)-mediated pathophysiological processes. NF-xcexaB-mediated processes occur in inflammatory diseases, immunological disorders, septic shock, transplant rejection, radiation damage, reperfusion injuries after ischemia, thromboses or in complex, chronic inflammatory disorders such as arteriosclerosis.
The Pharmacological Action of Inhibitors of Nuclear Factor Kappa B
Nuclear factor kappa B (NF-xcexaB) is a dimeric protein complex occurring in many tissue cells and in particular in blood cells. NF-xcexaB takes on a particular role in the control of the expression of genes which have an NF-xcexaB binding sequence (5xe2x80x2-GGGPuNNPyPyCC-3xe2x80x2) in their promoter sequence. To this extent, NF-xcexaB is a transcription factor. The physiological activity of NF-xcexaB in the control of gene expression, however, is subject to a regulation principle, in which NF-xcexaB is released from a complex with the protein IxcexaB in order to be translocated as a transcription factor in the cell nucleus of gene activation. The regulation principle for the release of active NF-xcexaB from a complex with the protein IxcexaB is still not known in detail.
Likewise, it is not known how the formation of homodimeric and heterodimeric NF-xcexaB protein complexes takes place. NF-xcexaB acts on gene activation as a dimeric transcription factor. The dimerization can take place under the structurally related transcription factors Rel A, Rel B, c-Rel, p50 or p52, which form a family of transcription factor proteins. In the dimerization of the subunits to the NF-xcexaB, there can also already be a regulation principle for the control of the genes later described in greater detail, which is still not known.
A crucial feature of NF-xcexaB compared to other transcription factors is that NF-xcexaB is a primary transcription factor. Primary transcription factors are already present in the cell in inactive (usually complex-bound) form and are released after an appropriate stimulus in order to be able to display their action very rapidly. Primary transcription factors are not first formed by the activation of the associated gene and subsequent transcription and translation.
This property of NF-xcexaB, the formation of homodimeric or heterodimeric Rel proteins and the formation of an inactive protein complex with an IxcexaB protein, offer very different points of attack for pharmacologically active substances than the points of attack of the de novo biosynthesis of transcription factors. For the sake of completeness, it may be mentioned that the genes for the formation of NF-xcexaB (genes of the Rel family) and the genes for the formation of the IxcexaB proteins (gene family comprising the genes for IxcexaB-xcex1, IxcexaB-xcex2, p105/IxcexaB-xcex3, p100/IxcexaB-xcex4, IxcexaB-xcex5 and others) for their part are of course also subject to regulation, which can be points of attack for pharmaceutically active substances. Thus it is known that the expression of the constitutively formed IxcexaB proteins p105 and p100 is increased by stimuli which also activate NF-xcexaB, such as tumour necrosis factor-xcex1 (TNF-xcex1) or phorbol myristate acetate (PMA).
A regulation mechanism is described in the literature in which it is shown that the overexpression of IxcexaB binds active NF-xcexaB and thus inactivates it. This also applies if the NF-xcexaB has already entered into a complex with the DNA (P. A. Baeuerle, T. Henkel, Annu. Rev. Immunol. 12, 141-179, 1994). From this it can be concluded that there are a number of specific points of attack in the biochemical function of NF-xcexaB and IxcexaB proteins which should make it possible to inhibit an undesirable, pathophysiological, NF-xcexaB-dependent gene activation selectively.
A chemical compound which selectively inhibits the function of NF-xcexaB or the function of IxcexaB proteins or IxcexaB genes to an increased extent should be able to be used as a pharmaceutical for the suppression of NF-xcexaB-mediated disease processes.
Primarily, NF-xcexaB can promote all pathophysiological processes in which genes are involved which have the NF-xcexaB binding sequence in their promoter. Mainly, these are genes which play a crucial causal role in immunological complications, in inflammatory diseases, autoimnmune disorders, septic shock, transplant rejection, thromboses or else alternatively in chronic inflammatory diseases such as arteriosclerosis, arthritis, rheumatism and psoriasis.
NF-xcexaB binding sequences contain, for example, the promoters of receptors of lymphoid cells (T-cell receptors), of MHCI and MHCII genes, of cell adhesion molecules (ELAM-1, VCAM-1, ICAM-1), of cytokines and growth factors (see also the following table). Furthermore, NF-xcexaB binding sequences are found in the promoters of acute phase proteins (angiotensinogen, complement factors and others).
A chronically increased or acutely overshooting activation of the genes mentioned leads to various pathophysiological processes and syndromes.
The rapid and overshooting production of cytokines of the inflammatory reaction (TNFxcex1, interleukin-2, interleukin-6, interleukin-8 and others) and of the adhesion molecules (ELAM-1, ICAM-1, VCAM-1) in leukocytes, in particular in macrophages and also in endothelial cells, is a causal feature of processes which often run a fatal course in the case of septic shock; or in the case of radiation damage and in the case of transplant rejection often leads to considerable complications. Inhibitors which prevent the NF-xcexaB-mediated gene expression intervene very early in some diseases in the expression of pathophysiological changes and can therefore be a very effective therapeutic principle. An example is also NF-xcexaB inhibitors for diseases which are to be attributed to an overexpression of acute-phase proteins. An undesirable overexpression of acute-phase proteins can cause a complex general reaction in which tissue damage of very different types, fever and local symptoms such as inflammation and necroses can occur. Usually, the blood picture is changed. NF-xcexaB strongly induces, for example, the serum amyloid A precursor protein in the liver in the course of induction of acute-phase proteins.
For example, the NF-xcexaB-mediated gene expression of the interleukin-2-(II-2) gene can be inhibited.
Interleukin-2 is a cytokine which plays a central role in various inflammatory processes, inter alia, as a hematopoietic growth factor (Annu. Rev. Immunol. 1994, 12: 141-79). The promoter of the interleukin-2 gene is NF-xcexaB dependent. An inhibitor of NF-xcexaB stimulation thus opens up the possibility of preventing overshooting of II-2 production and thus of treating inflammatory processes.
In the case of other syndromes such as tissue damage after reperfusion or cirrhosis of the liver, inhibitors of NF-xcexaB-mediated gene expression can likewise represent an important therapeutic advance. There is evidence that NF-xcexaB-controlled genes are induced as a result of oxidation reactions which lead to oxidative stress after reperfusion of ischemic tissue. In this way, an overexpression of cytokines and cell adhesion molecules in the ischemic tissue causes excessive recruitment of infiltrating alymphocytes. The recruited lymphocytes contribute causally to the tissue damage.
The involvement of NF-xcexaB-controlled gene expression is evident in a number of neurodegenerative disorders. In particular in the case of nervous diseases in which the redox state of cells of the neuronal tissue is disturbed, a therapeutic benefit is ascribed to the selective inhibition of genes having an NF-xcexaB binding sequence. A disturbed redox state of neuronal cells is assumed in the case of ainyotropic lateral sclerosis and in Down""s syndrome.
It is known that NF-xcexaB is a frequently encountered transcription factor in neuronal tissue and that NF-xcexaB is a redox potential-controlled transcription factor in the brain (P. A. Bauerle, T. Henkel, Annu. Rev. Immunol. 12, 141-179, 1994). A formulation of the genes which are induced by NF-xcexaB is shown in Table 2.
In addition to the already mentioned genes, whose activity is controlled by the release of NF-xcexaB and which particularly play a role in inflammatory processes, septic shock and transplant rejection, NF-xcexaB-controlled genes in viruses may also be mentioned and those which produce oncogenic cellular changes (oncogenes such as c-myc, c-rel, melanoma growth stimulating activity MGSA). In these genes too, selective inhibition of NF-xcexaB binding is a promising, therapeutically utilizable concept. The gene expression of lymphotrophic viruses such as HIV, HTLV and Epstein-Barr virus is activated either directly or by NF-xcexaB or NF-xcexaB is induced in the infected host cell, which is favourable to virus replication. In addition, HIV has an NF-xcexaB-positive action on gene expression in the cytomegalovirus (CMV) and adenovirus. Antiviral effects with NF-xcexaB inhibitors are conceivable here too.